The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Shock absorbers are used in conjunction with automotive suspension systems to absorb unwanted vibrations which occur during driving. Shock absorbers are generally connected between the sprung portion (body) and the unsprung portion (wheels) of the automobile. In a monotube shock absorber, a piston is located within a working chamber defined by a pressure tube of the shock absorber, with the piston being connected to the sprung portion of the automobile through a piston rod. The pressure tube is connected to the unsprung portion of the vehicle by one of the methods known in the art. Because the piston is able, through valving, to limit the flow of damping fluid between opposite sides of the piston when the shock absorber is compressed or extended, the shock absorber is able to produce a damping force which damps the unwanted vibration which would otherwise be transmitted between the unsprung portion and the sprung portion of the automobile.
In a dual tube shock absorber, a piston is located within a working chamber defined by a pressure tube of the shock absorber, with the piston being connected to the sprung portion of the automobile through a piston rod. A reserve tube surrounds the pressure tube to define a reserve chamber with a base valve assembly being located between the working chamber and the reserve chamber. The reserve tube is connected to the unsprung portion of the vehicle by one of the methods known in the art. Valving in the piston limits the flow of damping fluid between an upper side and a lower side of the piston when the shock absorber is extended to create a damping load. Valving in the base valve assembly limits the flow of damping fluid between the working chamber and the reserve chamber when the shock absorber is compressed to create a damping load. The piston also includes a check valve for replenishment of fluid on the upper side of the piston during a compression stroke and the base valve assembly includes a check valve for replenishment of fluid on the lower side of the piston during an extension stroke.